Long term follow up from phase 2 studies shows sustainability of response with masitinib.

PARIS, Nov. 12, 2013 (GLOBE NEWSWIRE) -- AB Science SA (NYSE Euronext - FR0010557264 - AB), a pharmaceutical company specialized in research, development and marketing of protein kinase inhibitors (PKIs), following the press release from November 11th that announced the phase 3 study's success in the futility analysis, further specifies important points concerning availability of phase 3 data, number of patients treatable and sustainability of response generated by masitinib observed in phase 2.

The read-out of the phase 3 study in mastosytosis is expected by end of 2014. Phase 3 study was accelerated and expanded recently outside of Europe and the USA, in Russia, India and Latin America.

Indolent Systemic Mastocytosis is an orphan disease with no approved drug currently registered. Masitinib received orphan drug status designation in mastocytosis, both from EMA and FDA.

Mastocytosis is an orphan disease characterized by an abnormal proliferation of mast cells either in bone marrow only or in several tissues. Mastocytosis comes in two main forms: indolent and aggressive. Indolent mastocytosis can be either cutaneous or systemic. The prevalence of Indolent Systemic Mastocytosis (ISM) is estimated at between 1/40,000 and 1/20,000[1] of the general population. The symptoms and handicaps are severe in about one third of the patients, hence an estimated target population for masitinib ranging from 1/120,000 to 1/60,000 of the general population.

Since the prevalence of Indolent Systemic Mastocytosis is reputed to be comparable across countries, the target population for masitinib could reach 20,000 adult patients in the world annually.

The fact that the phase 3 study in mastocytosis passed futility analysis is in line with phase 2 results.

Two phase 2 studies enrolled 46 patients suffering from systemic mastocytosis. Masitinib decreased the flush frequency by 54%, decreased the pruritus score by 45%, improved the depression status by 40% and decreased the fatigue score by 52% from baseline. The two studies generated results consistent with each other despite the fact that the first one enrolled patients without the c-kit 816 mutation and the second one with this mutation, suggesting that masitinib acts by inhibiting not only c-Kit but also Lyn, in blocking the release of the mediators by the mast cell.

In addition, long term followup data of the two phase 2 studies showed sustainability of responses generated by masitinib. Two-thirds of the patients decided to enroll in the extension phase of the study ; 61% patients were treated for more than 1 year and 25% were still under masitinib after 5 years.

Aboutmasitinib

Masitinib is a new orally administered tyrosine kinase inhibitor that targets mast cells, important cells for immunity, as well as a limited number of kinases that play key roles in various cancers. Owing to its novel mechanism of action, masitinib can be developed in a large number of conditions in oncology, in inflammatory diseases, and in certain diseases of the central nervous system. Through its activity of inhibiting certain kinases that are essential in some oncogenic processes, masitinib may have an effect on tumor regression, alone or in combination with chemotherapy. Through its activity on the mast cell and certain kinases essential to the activation of the inflammatory cells and fibrosing tissue remodeling, masitinib can have an effect on the symptoms associated with some inflammatory and central nervous system diseases.

About AB Science

Founded in 2001, AB Science is a pharmaceutical company specializing in the research, development and commercialization of protein kinase inhibitors (PKIs), a new class of targeted molecules whose action is to modify signaling pathways within cells. Through these PKIs, the Company targets diseases with high unmet medical needs (cancer, inflammatory diseases, and central nervous system diseases), in both human and veterinary medicines.

AB Science has developed a proprietary portfolio of molecules and the Company's lead compound, masitinib, has already been registered for veterinary medicine in Europe and in the USA, and is pursuing ten on-going phase 3 studies in human medicine in GIST, metastatic melanoma expressing JM mutation of c-Kit, multiple myeloma, mastocytosis, severe persistent asthma, rheumatoid arthritis, Alzheimer's disease, progressive forms of multiple sclerosis, and in Amyotrophic Lateral Sclerosis. The company is headquartered in Paris, France, and listed on Euronext Paris (ticker: AB).

This document contains prospective information. No guarantee can be given as for the realization of these forecasts, which are subject to those risks described in documents deposited by the Company to the Authority of the financial markets, including trends of the economic conjuncture, the financial markets and the markets on which AB Science is present.